Enteral therapy is a method of nutritional support achieved typically through pre-pyloric intubation of a nasoenteric feeding tube. Tracheobronchial aspiration, which may lead to esophageal regurgitation, has been recognized as a risk of intragastric or pre-pyloric tube feeding. Post-pyloric intubation of the enteral feeding tube has been identified as a means of reducing the risk of tracheobronchial aspiration and esophageal regurgitation. To effect post-pyloric or duodenal intubation, it is necessary to obtain transpyloric passage of the distal end of the feeding tube. This may be achieved by endoscopy, fluoroscopy or x-ray techniques for uncooperative or comatose patients, or those patients having impaired peristaltic movement within the gastrointestinal tract. Preferably, however, transpyloric passage is most safely achieved by use of peristaltic movement of the stomach walls to cause the distal end of the feeding tube to migrate through the pylorus.
A recent study has suggested that there is no advantage in distally weighted feeding tubes as opposed to unweighted feeding tubes in achieving transpyloric passage and duodenal intubation. Levenson, R. et al., Do Weighted Nasoenteric Feeding Tubes Facilitate Duodenal Intubations?, Journal of Parenteral and Enteral Nutrition, vol. 12, pp. 135-137 (1988). However, not only does this study use an unusually large, and therefore, stiff 10 Fr. tube, it also acknowledges that the effect of various weighted bolus designs on duodenal intubations was not evaluated. It is an object of the present invention to develop a distally weighted feeding tube which maximizes use of peristaltic contractions to obtain a high incidence of successful transpyloric passage.